The present invention relates to a method for adjusting a treatment machine, in particular a bottle cleaning machine.
More particularly, it relates to a method of adjusting a treatment machine, in which a transporting chain provided for transportation of objects to be treated is guided in loops, in particular meanderingly, through one or several treatment stations in a machine housing and is driven at least at two locations by a drive, so that in a normal operation they are synchronized and adjusted relative to one another, so that the transporting chain in its guides is neither over tightened nor compressed.
Such treatment machines are known in particular as bottle cleaning machines. In such bottle cleaning machines bottles are guided in bottle carriers through the cleaning stations of the machine. The machine has individual holders arranged in a horizontal row for receiving of the bottles, which are mounted with their ends on chain members of the roller chains. The roller chains are guided by guiding rails and folded meanderingly in a vertical plane in the machine housing. In order to maintain friction losses, chain forces and wear within certain limits, the transporting chains of known flat cleaning machines are driven at several locations. This is usually performed by means of horizontal and mutually parallel drive shafts, on which each corresponding chain pair is arranged for engaging in the transporting chain. Typically two-eight drive shafts are provided.
These drive shafts must be driven synchronously, so that the transporting chain is not subjected between two successive drive shafts to significant and usually disadvantageous pressing and pulling forces. Otherwise, the transporting chain and its guiding rails can be damaged or prematurely worn out. The synchronization of the drive shafts can be provided by mechanical means with shafts, transmissions, or chains, or by an electronic synchronous regulation, when several drive motors are provided for each drive shaft or each group of drive shafts.
A chain gap must be adjusted between two drives arranged successively in a pulling direction of the transporting chain so that the transporting chain is guided not to loosely and not too tightly. For adjusting the desired chain gap, the relative rotary position of the successive drive shafts is changed. When the synchronization of the drives is performed by mechanical means, the chain gap can be adjusted by displacement of couplings or chain drives. With electronic synchronization, the angular position of the neighboring drives can be changed by the asynchronous actuation of the individual drives.
In known adjustment processes, the chain tensioning is performed by a person involved in maintenance, by optical observation of the chain length. This approach has basically the disadvantage that for performing of the method a trained person is needed which has a substantial experience in this area. This means that such a method involves high time and labor expenses and also has the risk that the adjustment can be made in erroneous way. Furthermore, for performing of the right chain adjustment, in some cases also the length of the chain inside the cleaning station must be determined. This has the advantage that for this purpose the cleaning fluids must be removed. Since however erroneous adjustments result in a fast wear of the transporting chain, guides and drives, there is therefore a demand for a less expensive adjusting method which is reliable and reproducible at anytime.
Accordingly, it is an object of the present invention to provide an improved method for adjusting treatment machine, which is substantially automated and can be performed in a simple manner without trained and experienced personnel.
In keeping with these objects and with others which will become apparent hereinafter, one feature of present invention resides, briefly stated, in a method which has the following steps.
a. Two drives which follow one another in a forward direction of the transporting chain are selected;
b. The selected drives are driven asynchronously so that they tightly pull or compress the chain portion located between them by producing a length difference, and a parameter which is dependent from the drive moment of one or both drives is measured;
c. When the parameter reaches or exceeds a fixed value, the drives are driven asynchronously in direction of a reduction of the previously produced length difference by a predetermined amount;
d. The so adjusted relative position of the both drives with respect to one another is subsequently maintained, in particular during the synchronous operation of the drives;
e. The preceding method steps are used for further drives until the chain lengths are adjusted in all portions to be adjusted.
The inventive method has the advantage that it is composed of simple method steps, which are performed in dependence on simple parameters. For its performance, no trained or experienced personnel is needed. It can be performed automatically in a simple manner. The method is simple and reliable since special measuring devices on or in the machine, for example for measurements of the chain tensioning and position are dispensed with.
The predetermined value for the parameter which is dependent from the drive motor is determined so that the corresponding drive moment substantially exceeds a drive moment which is sufficient for tightening of the corresponding chain portion and nevertheless is not so great that a component of the treatment machine, in particular the transporting chain or the drive motor can be unpermissibly loaded. The amount determined for the reduction of the previously produced length difference is selected so that the chain portion to be adjusted sits in its guides not to loosely and not too tightly.
The method is preferably performed outside of the normal operational time, in particular when the treatment machine is maintained at certain times. Basically the method can be performed also during the normal operation, by driving of two drives arranged one after the other in the pulling direction with insignificantly different speeds and forming a parameter which is used for the indication of the tightly pulled or compressed chain portion, for example from the difference between the drive moments of the both drives. During the operation of the treatment machine, the transporting chain, due to wear and pull load, becomes longer after a certain time. Since it is an endless chain, conventionally in a treatment machine a portion is provided for the receipt of the thusly produced excessive chain length. In particular, the transporting chain is suspended so that it more or less sags in form of a loop. It is to be understood that the inventive method is not performed with two drives which are arranged before and after such a compensating portion.
In accordance with another embodiment of the inventive method for a treatment machine with a compensation portion, it is provided that the drive direction of the drive between the chain portion to be adjusted and the compensation portion together with a selected drive and/or all remaining drives together with the other selected drive are operated synchronously. This feature guarantees that for example during a tight pulling of the individual chain portions the neighboring chain portion is not compressed or vice versa. When as provided, all preceding or all subsequent drives are operated synchronously, such a compression in the neighboring chain portions, which can produce an additional counter moment with falsified the measuring results, is prevented with a corresponding advantage. In known treatment machines, as a rule, all chain portions between each two drives are designed differently with respect to their length and the geometric shape of their guides. In this case, it is especially advantageous when for each chain portion to be adjusted, a special parameter which depends on the drive moment is provided, since the optimal chain adjustment must be provided in general in each chain portion with another drive moment.
The same is true for the amount, by which the drive after reaching of a predetermined drive moment must be xe2x80x9cadjusted backxe2x80x9d. In accordance with a further embodiment of the inventive method, it is provided that for each chain portion to be adjusted, a special predetermined amount for the reduction of the previously obtained length difference is provided.
An accurate adjustment of the corresponding chain portion can be also provided when not only the tightly pulled or compressed condition of the chain portion is determined, but also when both conditions are determined. In a variant of the inventive method it is therefore provided that in the frame of the method steps b and c the chain portion to be adjusted is tightly pulled first for obtaining a first parameter value, and then with registration of the chain length which is required for it, is compressed until it reaches a second parameter value, or vice versa, and the amount of the subsequent adjustment step depends on the register chain length. The adjustment step is also not strictly predetermined from the tightly pulled or compressed adjustment, but instead it depends on the length difference of the chain portion between the compressed and the tightly pulled position, or in other words from both positions.
In accordance with a preferable embodiment of the present invention, the drives are controllable electrically, and the method is performed automatically by means of a microprocessor which is programmed in a suitable way. A programmable microprocessor provides nowadays the simplest, multi-facet and cost-favorable possibility for realization of an automatic control. In this case, it is especially advantageous when the drives are provided with rotary sensors for determination of their relative angular positions, the angular positions are stored, and the synchronization is performed from electrical path via the control of the drive. Such an electrical synchronization, requires in particular during the use of a programmable microprocessor, only a small expense without expensive mechanical components.
The inventive method can be performed particularly simple and cost favorable when the drives have electric motors whose current consumption is measured as a drive moment-dependent parameter. In this embodiment, no additional sensors are needed for the measurement of the drive moment. Also, when the invention is described here in connection with the rotatable electric motors, such drives also can include electric linear motors. In this case, the terms rotary angle and drive moment must be replaced with the terms displacement and drive force.
In accordance with a preferable embodiment of the inventive method which is characterized by a particularly simple control process, an electrical drive which is arranged first in a forward direction of the transporting chain after the compensating portion and the chain portion to be adjusted is determined, and the subsequently arranged second electrical drive, are operated synchronously with all subsequent drives in the forward direction, until its current consumption exceeds a predetermined value. Then the second drive together with all subsequent drives are stopped, turned back by a predetermined rotary angle opposite to the forward direction and subsequently fixed, the method is proceeded with the third and all subsequent drives correspondingly until the last chain portion arranged before the compensation portion is adjusted. For the case when the available drive control does not allow return operation of the drive, another method is recommended which also has an especially simple control course. This method starts as the above described method, however after the first stop of the second drive, the first drive is turned by a predetermined rotary angle in the forward direction and subsequently is fixed together with the second drive. The method is proceeded with the third and all subsequent drives correspondingly, until the last chain portion arranged before the compensation portion is adjusted, and before the chain portion to be adjusted and after the arranged drive it is operated correspondingly synchronously or together.
In accordance with a further embodiment of the invention, the inventive method provides in addition to a correct chain adjustment also a value of the chain elongation required for the normal operation of the treatment machine in running, and thereby the connected chain wear.
In accordance with a further method it is provided that the chain length difference occurring in each adjustment is measured and stored, and their sum is evaluated as an indicator for the total chain elongation average and/or the chain wear. It is to be understood that in a treatment machine with a compensating portion for the chain leg also a modified method can be used, in which the length of the chain sagging is measured in the compensating portion and an indicator for the total chain length and/or chain wear is evaluated.
The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.